It is anticipated that communications via information technology (IT) will broaden from the text information of related art to encompass objects in a range of information media, such as video images and conversations recorded by individuals, broadcast images and cinematic images, product information and sensor information, production records and transport records, geographical and climate information that changes from moment to moment, and so forth, and that usage contexts will dynamically broaden to a range of contexts such as information-providing household appliances, vehicle-mounted terminals, electronic tags, public transport systems, industrial production and distribution sites, store counters, and so forth.
One of the driving factors in this is next-generation information retrieval and analysis technologies which, rather than searching for information with the emphasis only on text in homepages as in current home computers, respond to new communication needs in all contexts—personal life, business and so forth.
In a related art information retrieval and analysis technology, the input of a keyword is received and information that matches the inputted keyword is retrieved from information on a network, and is presented in order of numbers of hits. In addition, there are automatic keyword extension technologies that display keywords that can be used together with the inputted keyword, technologies that recommend products and the like in accordance with data on personal recommendations from large numbers of users, and so forth.
According to these technologies, a user can retrieve many kinds of information containing an inputted keyword. However, this information statistically bundles results of retrievals by large numbers of other users, and is not information that is particular to the actual needs and wants of the user.
In these times of information overload, the number of people who cannot deal with the explosive increase in amounts of information and who struggle to keep track of information selection criteria is currently increasing. For users who have problems of being unable to choose the information, activities and suchlike that they want, an information retrieval and analysis technology in which both simple retrieval and a systematic way of thinking before retrieval are found together is being called for.
Accordingly, the present inventors have proposed information retrieval and analysis technologies (Japanese Patent Application Nos. 2008-036342 and 2008-036356) that employ a laddering technique to draw out the needs and values of a user in a dialogue by iteration of questions that progressively dig deeper, draw out needs relating to services and contents, which are difficult for the user themself to express, by iteration of the dialogue between the user and the system, and retrieve matching information from a wide variety and large quantity of services and contents.
This dialogue-based retrieval system generates question texts on the basis of domain knowledge and presents the questions to the user, analyses answers from the user at the semantic level by intention analysis, and implements retrieval by matching the information drawn out from the user and analysis of previous retrieval targets (for example, results of analysing what needs to be understood from the user's answers) with the results of analysis of retrieval target data.